JPH04349941A - anion exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new anion exchanger, particularly a crosslinked anion exchanger with excellent heat resistance.

0002

BACKGROUND OF THE INVENTION Conventionally, as anion exchange resins, various resins having various anion exchange substances such as amine substances such as primary to tertiary amines and quaternary ammonium as functional groups are known. Among these, trimethylbenzylammonium salt type salts in which trimethylamine is covalently bonded to the benzyl group of a polyvinyl aromatic compound are particularly widely used because of their excellent ion exchange ability. However, the trimethylbenzylammonium salt type is not suitable for long-term use at high temperatures because the ammonium salt decomposes and the exchange group falls off under high-temperature conditions. In addition, strong basic anion exchange resins other than the trimethylbenzylammonium salt type are known in which the trimethyl group is replaced with other alkyl groups such as triethyl group, but the aromatic ring and quaternary ammonium group Most of the atoms are bonded through -CH2- (methylene group).

Japanese Patent Publication No. 2-42542 describes a crosslinked copolymer of an aromatic monovinyl hydrocarbon and an aromatic divinyl hydrocarbon, -Cn H2n-X (wherein, X is a chlorine or bromine atom, and -Cn H2n is There is a description that it is a strong anion exchanger obtained by reacting a quaternary amine with a haloalkyl group represented by (1 to 4 alkylene groups), but specifically, it is described that the above n is 1. Moreover, if n is 3 or 4, if manufactured according to the method described in this document, the target product -(CH2)3- or -(CH2)4 - indicates that only a part of the anion exchange groups in the entire resin is present, and the heat resistance is not improved. Moreover, this document does not describe the heat resistance of the resin.

0004

[Problems to be Solved by the Invention] Therefore, an anion exchanger having higher heat resistance has been desired.

[0005]

[Means for Solving the Problems] That is, the present invention provides a crosslinked anion exchanger, wherein the exchanger has the following general formula (a
) contains a structural unit having a quaternary ammonium group and a unit derived from an unsaturated hydrocarbon group-containing crosslinking monomer, and 90% or more of the anion exchange groups of the exchanger are represented by the general formula (a). -RN+ R1 R2 R
3. It relates to a crosslinked anion exchanger characterized by having as a group represented by .X-.

[0006]

[Case 2]

[In the formula, R represents a polymethylene group (including a cyclic hydrocarbon) having 3 to 18 carbon atoms. R1, R2
, R3 each independently represent a hydrocarbon group or an alkanol group having 1 to 8 carbon atoms. The benzene ring in formula (a) may be substituted with an alkyl group or a halogen atom, or may be fused with another aromatic ring. X represents an anion] This anion exchanger of the present invention has excellent heat resistance,
It can be used in various fields where a heat-resistant anion exchanger is required. The anion exchanger in the present invention has a quaternized substituted ammonium group and can adsorb anions through ionic interaction. The present invention will be explained in detail below. In the general formula (a), R is a polymethylene group having 3 to 18 carbon atoms, but these polymethylene groups also include cyclic hydrocarbons. Preferably, it is a polymethylene group having 3 to 10 carbon atoms, and a cyclic saturated hydrocarbon group such as a cyclohexylene group is present, for example.

[0008]

[Chemical 3]

[0009] etc. are also preferable. In addition to a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, R1, R2, and R3 may have a cyclic hydrocarbon group such as a cyclohexyl group via them. Alternatively, alkanol groups having a hydroxyl group bonded thereto may also be mentioned. An example of a group having a cyclic group is a group such as a cyclohexylmethyl group. Examples of substituents on the benzene ring in general formula (a) include alkyl groups such as ethyl groups, and halogen atoms such as chlorine, bromine, and iodine. Examples include naphthalene rings. Such a benzene ring is -R-N+
Those having no substituent other than R1 R2 R3 .X- are preferred, but among the above substituents, those having a methyl group, ethyl group, etc. are also preferably used. General formula (
X- in a) is not particularly limited as long as it is an anion, but for example, halogen ions such as Cl-, Br-, I-, sulfate ions, NO3-, OH-,
Other anions such as p-toluenesulfonate ion may be mentioned. In addition, in the case of a divalent anion such as a sulfate ion, one anion molecule is adsorbed to two molecules of the structural unit of general formula (a). The present invention provides -RN+ R1 R2 R3 in the general formula (a).
It is characterized in that the group represented by X- accounts for 90% or more of all anion exchange groups in the crosslinked anion exchanger. That is, in the present invention, when R is an acyclic polymethylene group, R is a linear polymethylene group having 3 to 18 carbon atoms, and the group represented by -N+ R1 R2 R3 ・X- is a linear polymethylene group. It is attached to the end. In other words, even if R has a large number of carbon atoms, if R is branched or if the quaternary ammonium group is bonded in the middle of R rather than at the end, the anion exchange of the exchanger will be difficult. This means that it accounts for less than 10% of the base. In this respect, the anion exchanger of the present invention differs from known anion exchange resins, and thereby also has improved heat resistance. The anion exchanger of the present invention is -N+ R1 R2 R3
・It must contain an anion exchange group represented by Preferably. The anion exchanger of the present invention is produced, for example, by the following production method. The structural unit represented by the general formula (a) is usually provided as a precursor monomer represented by the following general formula (b).

0010

[C4]

[In the formula, R has the same definition as in the general formula (a) above, and Z represents a group having substitution activity such as bromine, chlorine, iodine, or tosyl group. The benzene ring (b) may be substituted with an alkyl group or a halogen atom, or may be condensed with another aromatic ring to form a naphthalene ring or the like. ] As the base monomer having the -R-Z group of the precursor monomer represented by the above general formula (b), styrene is preferred, but other examples include ethylvinylbenzene, vinyltoluene, vinylnaphthalene, and the like. This precursor monomer is typically
science polymer chemist
ry edition, volume 20, (198
2) It can be manufactured by a known technique as described in "P.3015". That is, it can be obtained by reacting the chloromethylated base monomer (for example, chloromethylstyrene) with polyalkylene dihalide by the Grignard method. The polyalkylene dihalide mentioned here is one having a polymethylene group having 3 to 18 carbon atoms, preferably one having a polymethylene group having 3 to 10 carbon atoms. When the number of carbon atoms is small, it is difficult to expect the heat resistance effect of the present invention, and when the number of carbon atoms is large, the exchange capacity per unit weight decreases, so it is not practical from an industrial perspective. . On the other hand, the precursor monomer of general formula (b) can also be obtained by reacting the chlorinated base monomer (chlorstyrene) with polyalkylene dihalide by the Grignard method. Examples of the unsaturated hydrocarbon group-containing crosslinking monomer necessary to form the anion exchanger of the present invention include divinylbenzene, trivinylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, ethylene glycol dimethacrylate,
Examples include diethylene glycol dimethacrylate and trimethylolpropane trimethacrylate. Among them, divinylbenzene is preferred. In the anion exchanger of the present invention, a copolymerization component may be introduced using a precursor monomer and an addition polymerizable monomer other than a crosslinking monomer, if necessary. Specific examples of this addition polymerization monomer include:
Styrene, methacrylic acid esters such as methyl methacrylate or ethyl methacrylate, propyl methacrylate, acrylic acid esters such as methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid, acrylonitrile, methacrylonitrile, ethyl vinyl benzene, vinyltoluene, vinylnaphthalene,
Examples include butadiene and isoprene.

[0012] The anion exchanger of the present invention uses these raw material monomers to form a crosslinked copolymer, and then the "-R-Z" of the structural unit derived from the precursor monomer represented by the general formula (b) '' is produced by introducing an ammonium group into the site. This crosslinked copolymer is produced according to known techniques, and is usually produced into a spherical crosslinked copolymer. That is, the precursor monomer forming the structural unit represented by the general formula (a), that is, the precursor monomer represented by the general formula (b), the unsaturated hydrocarbon group-containing crosslinkable monomer, and the addition polymerizable monomer used as necessary. The monomers are subjected to suspension polymerization in the presence of a polymerization initiator according to a known method.

[0013] The precursor monomer imparting the structural unit of general formula (a) is used in an amount of 20 to 10
0% by weight used. Further, the composition ratio of the unsaturated hydrocarbon group-containing crosslinking monomer has an important influence on the insolubilization of the anion exchanger of the present invention. Normally, if the composition ratio of the crosslinking monomer containing unsaturated hydrocarbon groups is low, the anion exchanger cannot be insolubilized, and conversely, when the composition ratio of the crosslinking monomer containing unsaturated hydrocarbon groups is high, the anion exchanger cannot be insolubilized. This has no practical meaning because the ratio of ion exchange components in the exchanger becomes low. Therefore, when producing the anion exchanger of the present invention, the usage ratio of the unsaturated hydrocarbon group-containing crosslinking monomer is usually 0.1% to 55% based on the total monomers of the raw material.
is used, particularly preferably in a weight proportion of 0.5% to 25%.

On the other hand, the usage ratio of the addition polymerizable monomer as a copolymerization component is 0 to 50% based on the total monomers of the raw materials.
, preferably in a weight ratio of 0 to 20%. In addition, as a polymerization initiator used during suspension polymerization, dibenzoyl peroxide, lauroyl peroxide, t-butyl hydroperoxide, azobisisobutyronitrile, etc. are used, and usually, based on all monomers, 0.1-5% by weight
Used to some extent. Although the polymerization temperature varies depending on the type and concentration of the polymerization initiator, it is usually selected and used within the range of 40 to 100°C. Methods for introducing ammonium groups into the crosslinked copolymer thus produced include known methods, such as suspending the resin in a solvent and adding NR1 R2 R3 (in the formula, R1 , R2 , R
3 is the same as defined in general formula (a)). Examples of the solvent used in this introduction reaction include water, alcohol,
Toluene, dioxane, dimethylformamide, etc. can be used alone or in combination. Further, the reaction temperature varies greatly depending on the type of substituted amine and the type of solvent, but is usually in the range of 20 to 100°C.

The anion exchanger of the present invention can then be obtained by converting the salt type into various anion types using known methods. As described above, the anion exchanger of the present invention to be produced is particularly characterized by the general formula (a) in which -R-N+ R1 R
2 Structural unit 20 having a group represented by R3 ・X-
~99.5% by weight, 0.1 to 55% by weight of structural units derived from unsaturated hydrocarbon group-containing crosslinkable monomers, and 0 to 55% by weight of structural units derived from other addition polymerizable monomers.
A composition comprising 20% by weight is preferred. As the anion exchanger of the present invention, when X is a hydroxide ion, it is used as it is, or when X is another anion, it is converted to a hydroxide type, and the itself is 0.1N hydroxide. Particularly preferred is one that satisfies the conditions that the exchange capacity remaining rate is 90% or more and the volume retention rate is 90% or more even when heated in a sodium aqueous solution at 100° C. for 60 hours. Further, the shape of the anion exchanger of the present invention is not particularly limited, and in addition to the bead-like shape as described in detail above, it may be in the form of beads, which have been made porous by a known method, fibrous, powder, plate-like, etc. The present application also includes various shapes such as a film shape.

[0016]

EXAMPLES The present invention will be explained in more detail with reference to examples below, but the present invention is not limited to the following examples.

Production Example 1 (Synthesis of ω-haloalkylstyrene) 100 g of chloromethylstyrene was stirred with metallic magnesium in nitrogen-substituted diethyl ether and left at 0° C. for 3 hours to form a magnesium composite. After replacing the solvent with nitrogen-substituted tetrahydrofuran, 1,3-dibromopropane and Li2CuCl4 were added dropwise at 0°C. After continuing the reaction at 0° C. for 5 hours, the resulting product was fractionated by distillation. 4-bromobutylstyrene: 0.3 Torr, 120°C
The yield was 35% based on the raw material chloromethylstyrene. Identification of 4-bromobutylstyrene was performed by the NMR method described in "Journal of Polymer Science Polymer Chemistry Edition, Volume 20, 1982, Page 3015".

(Synthesis of crosslinked ω-haloalkylstyrene) 96.4 parts by weight of the obtained 4-bromobutylstyrene and 3.6 parts by weight of industrial grade divinylbenzene (purity 55%, remaining main component is ethylvinylbenzene) 1 part by weight
．． Polymer beads were obtained in a yield of 90% by a suspension polymerization method in which 0 parts by weight of azobisisobutyronitrile was added and maintained at 70° C. for 18 hours under a nitrogen atmosphere.

(Synthesis of anion exchanger) 100 parts by weight of the obtained crosslinked 4-bromobutylstyrene was mixed with 3 parts by weight of dioxane.
00 parts by weight, stirred, and allowed to swell for 2 hours. Next, trimethylamine in an amount equivalent to 3 moles relative to the bromo group was added dropwise, and the suspension solution was allowed to react at 50° C. for 10 hours. After thoroughly washing the obtained anion exchanger with demineralized water, the salt form was converted into the chloride form. In this way, an anion exchanger having the following general performance was obtained. Exchange capacity 0.79meq/ml3.77m
eq/g Moisture 67.4% This anion exchanger is referred to as Sample A. The above general performance was measured in accordance with the method described in "Ion Exchange Resins, edited by Honda et al., Hirokawa Shoten, pp. 17-56."

Production Example 2 Production Example 1 except that in the synthesis of crosslinked ω-haloalkylstyrene, 4-bromobutylstyrene was changed to 92.7 parts by weight and industrial grade divinylbenzene was changed to 7.3 parts by weight. An anion exchanger was obtained in the same manner as in Example 1. In this way, an anion exchanger having the following general performance was obtained. Exchange capacity 1.10meq/ml 3.65m
eq/g moisture 54.1% This anion exchanger is referred to as sample B.

Production Example 3 In the synthesis of ω-haloalkylstyrene in Production Example 1,
By the same method as Production Example 2 except for using 1,6-dibromohexane instead of 1,3-dibromopropane,
An anion exchanger was obtained. In this way, an anion exchanger having the following general performance was obtained. Exchange capacity 1.16meq/ml 3.07m
eq/g Moisture 44.1% This anion exchanger is referred to as Sample C. In addition, the intermediate 7-bromoheptylstyrene is 0.4 Torr, 1
It was fractionated by distillation under the conditions of 20°C.

Production Example 4 In the synthesis of ω-haloalkylstyrene in Production Example 1,
Instead of 1,3-dibromopropane, 1,4-bis(
Production Example 1 except using bromomethyl)cyclohexane
An anion exchanger was obtained in the same manner as above. In this way, an anion exchanger having the following general performance was obtained. Exchange capacity 0.96meq/ml2.77m
eq/g Moisture 49.6% This anion exchanger is referred to as Sample D. Note that the intermediate 2-(4-bromomethylcyclohexylene)-ethylstyrene was fractionated by distillation under conditions of 0.25 Torr and 120°C.

Production Example 5 (Synthesis of 3-bromopropylstyrene) 83.16 g of p-chlorostyrene was stirred with metallic magnesium in nitrogen-substituted tetrahydrofuran and left at 35°C for 5 hours to form a magnesium complex. . This was mixed with tetrahydrofuran, 1,3-dibromopropane, Li2CuCl4
It was added dropwise to the mixed solution at 30°C. After continuing the reaction at 30° C. for 2 hours, the obtained product was fractionated by distillation. 3-
Bromopropylstyrene was obtained at 0.2 Torr and 110°C, and the yield based on the raw material p-chlorostyrene was 4.
It was 7%. The identity of 3-bromopropylstyrene is N
This was done by MR method.

(Synthesis of crosslinked 3-bromopropylstyrene) 92.7 parts by weight of the obtained 3-bromopropylstyrene and industrial grade divinylbenzene (purity 55%,
The remaining main component is ethylvinylbenzene), 1.0 parts by weight of azobisisobutyronitrile is added to 7.3 parts by weight,
Polymer beads were obtained in a yield of 79% by a suspension polymerization method maintained at 70° C. for 8 hours under a nitrogen atmosphere.

(Synthesis of anion exchanger) 10 parts by weight of the obtained crosslinked 3-bromopropylstyrene was mixed with 1 part by weight of dioxane.
00 parts by weight, stirred, and allowed to swell for 2 hours. Next, trimethylamine in an amount equivalent to 10 moles relative to the bromo group was added dropwise, and the suspension solution was allowed to react at 50° C. for 10 hours. After thoroughly washing the obtained anion exchanger with demineralized water, the salt form was converted into the chloride form. In this way, an anion exchanger having the following general performance was obtained. Exchange capacity 1.37meq/ml3.80m
eq/g Moisture 49.6% This anion exchanger is referred to as Sample E.

Example 1 (Short-term heat resistance test) Samples A and B obtained in the above production example
, C, D, and Diaion SA102 (trade name, manufactured by Mitsubishi Kasei Corporation) were subjected to a short-term heat resistance comparison test. Using a graduated cylinder, 10 ml of the anion exchanger was weighed out based on the chlor type, and the chlor type was converted into the free type using a column method. After performing centrifugal filtration to remove excess water, the mixture was placed in a test tube containing 40 ml of a 0.1N aqueous sodium hydroxide solution. After the test tube was placed in the autoclave, the autoclave was heated to conduct a short-term heat resistance test. The decrease in exchange capacity when heated at 100° C. for 60 hours was as follows. However, the exchanged capacity after the test was expressed based on the volume before the test.

[0027]

[Table 1]

Example 2 (Long-term heat resistance test) A long-term heat resistance comparison test was conducted on Sample E obtained in Production Example 5 above and Diaion SA10A (trade name, manufactured by Mitsubishi Kasei Corporation). Using a graduated cylinder, 100 ml of the anion exchanger was weighed out on a free form basis, and poured into a glass autoclave using demineralized water to give a total volume of 160 ml. This was heated at 50°C for 1 hour while blowing nitrogen into it to remove oxygen from the water. A long-term heat resistance test was conducted by sealing the container tightly and maintaining the heated state at 100° C. for 720 hours. The reduction in exchange capacity and volume after the long-term heat resistance test was as follows. However, the exchanged capacity after the test was expressed based on the volume before the test.

[0029]

[Table 2]

[0030]

[Effects of the Invention] The anion exchanger according to the present invention has excellent heat resistance and can be used in various fields where a heat-resistant anion exchanger is required.

Claims (1)

[Claims] Claim 1: A crosslinked anion exchanger containing a structural unit having a quaternary ammonium group represented by the following general formula (a) and a unit derived from a crosslinking monomer containing an unsaturated hydrocarbon group. and 90% or more of the anion exchange groups of the exchanger are -R- in the general formula (a).
A crosslinked anion exchanger having as a group represented by N+ R1 R2 R3 .X-. embedded image [In the formula, R represents a polymethylene group having 3 to 18 carbon atoms (including a cyclic hydrocarbon). R1, R2, and R3 each independently represent a hydrocarbon group or an alkanol group having 1 to 8 carbon atoms. The benzene ring in formula (a) may be substituted with an alkyl group or a halogen atom, or may be fused with another aromatic ring. X indicates anion]